Volvo 8.1L overheat

[MIKECHM]

Just purchased a 2002 Cobalt 240 with the 8.1L. Love it so far great boat. But when unload from the trailer after sitting a few days. When leaving the dock area we have a ways to go in no wake zone before being able to take off. The engine will start to run hot above 175 degrees and set the alarm off. I then shut the engine down for 5-10 minutes the temp goes down. I start to cruise and the temp runs normal the rest of the day. I could Idle for a long time and not get hot. Seems like just when starting out after sitting on the trailer a few days. This is a fresh water boat.

Thank you for any help any one has.

Mike Chmielewski
612-508-2029

 

[CV16]

Sticking thermostat maybe?

 

[CV16]

Also, if it's a new to you boat and you haven't replaced the impeller, do it.

 

[alldodge]

Agree, check the impeller and pump housing.

Merc has had similar issues with the 8.1 and the way some have fixed it, is once started, rev the engine a bit to get more water flowing. The VP uses a different pump but may be experiencing similar issues

 

[BRICH1260]

Probably a bad impeller.

 

[MIKECHM]

I would have thought a bad impeller also but after that the engine never runs hot the rest of the day. It's like it get air locked or something. Think I will change thermostat and impeller and see if that helps.

Thank you all for the ideas. Just joined this group and love it.

 

[MIKECHM]

Update. Replaced both the impeller and thermostat and now runs cool all the time. Thank you for your feedback